Ummmm, well, uh, I don't know. I've put together a bunch of quilted things in the last couple years and have done a lot of piecing. You see my squares are mostly 3.5". It takes a lot of those little squares to make a queen sized quilt.
All I can say is my favorite is one that:
A: backtacks
B: Sews forward and backward in a straight line.
C: has a good smooth foot controller
Joe